<html lang="en"> <head> <title>Literal Directive - Using as</title> <meta http-equiv="Content-Type" content="text/html"> <meta name="description" content="Using as"> <meta name="generator" content="makeinfo 4.13"> <link title="Top" rel="start" href="index.html#Top"> <link rel="up" href="Xtensa-Directives.html#Xtensa-Directives" title="Xtensa Directives"> <link rel="prev" href="Transform-Directive.html#Transform-Directive" title="Transform Directive"> <link rel="next" href="Literal-Position-Directive.html#Literal-Position-Directive" title="Literal Position Directive"> <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> <!-- This file documents the GNU Assembler "as". Copyright (C) 1991-2015 Free Software Foundation, Inc. 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A copy of the license is included in the section entitled ``GNU Free Documentation License''. --> <meta http-equiv="Content-Style-Type" content="text/css"> <style type="text/css"><!-- pre.display { font-family:inherit } pre.format { font-family:inherit } pre.smalldisplay { font-family:inherit; font-size:smaller } pre.smallformat { font-family:inherit; font-size:smaller } pre.smallexample { font-size:smaller } pre.smalllisp { font-size:smaller } span.sc { font-variant:small-caps } span.roman { font-family:serif; font-weight:normal; } span.sansserif { font-family:sans-serif; font-weight:normal; } --></style> </head> <body> <div class="node"> <a name="Literal-Directive"></a> <p> Next: <a rel="next" accesskey="n" href="Literal-Position-Directive.html#Literal-Position-Directive">Literal Position Directive</a>, Previous: <a rel="previous" accesskey="p" href="Transform-Directive.html#Transform-Directive">Transform Directive</a>, Up: <a rel="up" accesskey="u" href="Xtensa-Directives.html#Xtensa-Directives">Xtensa Directives</a> <hr> </div> <h5 class="subsubsection">9.52.5.4 literal</h5> <p><a name="index-g_t_0040code_007bliteral_007d-directive-2494"></a> The <code>.literal</code> directive is used to define literal pool data, i.e., read-only 32-bit data accessed via <code>L32R</code> instructions. <pre class="smallexample"> .literal <var>label</var>, <var>value</var>[, <var>value</var>...] </pre> <p>This directive is similar to the standard <code>.word</code> directive, except that the actual location of the literal data is determined by the assembler and linker, not by the position of the <code>.literal</code> directive. Using this directive gives the assembler freedom to locate the literal data in the most appropriate place and possibly to combine identical literals. For example, the code: <pre class="smallexample"> entry sp, 40 .literal .L1, sym l32r a4, .L1 </pre> <p>can be used to load a pointer to the symbol <code>sym</code> into register <code>a4</code>. The value of <code>sym</code> will not be placed between the <code>ENTRY</code> and <code>L32R</code> instructions; instead, the assembler puts the data in a literal pool. <p>Literal pools are placed by default in separate literal sections; however, when using the ‘<samp><span class="samp">--text-section-literals</span></samp>’ option (see <a href="Xtensa-Options.html#Xtensa-Options">Command Line Options</a>), the literal pools for PC-relative mode <code>L32R</code> instructions are placed in the current section.<a rel="footnote" href="#fn-1" name="fnd-1"><sup>1</sup></a> These text section literal pools are created automatically before <code>ENTRY</code> instructions and manually after ‘<samp><span class="samp">.literal_position</span></samp>’ directives (see <a href="Literal-Position-Directive.html#Literal-Position-Directive">literal_position</a>). If there are no preceding <code>ENTRY</code> instructions, explicit <code>.literal_position</code> directives must be used to place the text section literal pools; otherwise, <samp><span class="command">as</span></samp> will report an error. <p>When literals are placed in separate sections, the literal section names are derived from the names of the sections where the literals are defined. The base literal section names are <code>.literal</code> for PC-relative mode <code>L32R</code> instructions and <code>.lit4</code> for absolute mode <code>L32R</code> instructions (see <a href="Absolute-Literals-Directive.html#Absolute-Literals-Directive">absolute-literals</a>). These base names are used for literals defined in the default <code>.text</code> section. For literals defined in other sections or within the scope of a <code>literal_prefix</code> directive (see <a href="Literal-Prefix-Directive.html#Literal-Prefix-Directive">literal_prefix</a>), the following rules determine the literal section name: <ol type=1 start=1> <li>If the current section is a member of a section group, the literal section name includes the group name as a suffix to the base <code>.literal</code> or <code>.lit4</code> name, with a period to separate the base name and group name. The literal section is also made a member of the group. <li>If the current section name (or <code>literal_prefix</code> value) begins with “<code>.gnu.linkonce.</code><var>kind</var><code>.</code>”, the literal section name is formed by replacing “<code>.</code><var>kind</var>” with the base <code>.literal</code> or <code>.lit4</code> name. For example, for literals defined in a section named <code>.gnu.linkonce.t.func</code>, the literal section will be <code>.gnu.linkonce.literal.func</code> or <code>.gnu.linkonce.lit4.func</code>. <li>If the current section name (or <code>literal_prefix</code> value) ends with <code>.text</code>, the literal section name is formed by replacing that suffix with the base <code>.literal</code> or <code>.lit4</code> name. For example, for literals defined in a section named <code>.iram0.text</code>, the literal section will be <code>.iram0.literal</code> or <code>.iram0.lit4</code>. <li>If none of the preceding conditions apply, the literal section name is formed by adding the base <code>.literal</code> or <code>.lit4</code> name as a suffix to the current section name (or <code>literal_prefix</code> value). </ol> <div class="footnote"> <hr> <h4>Footnotes</h4><p class="footnote"><small>[<a name="fn-1" href="#fnd-1">1</a>]</small> Literals for the <code>.init</code> and <code>.fini</code> sections are always placed in separate sections, even when ‘<samp><span class="samp">--text-section-literals</span></samp>’ is enabled.</p> <hr></div> </body></html>